Random question 😂

So we have been potty trained for the last month and luckily it’s been nice weather so at home my girl is pretty much naked and when we are out I help pull her knickers and trousers down. She can get things off (slowly by working it out) which we are working on so we don’t have accidents but my issue is pulling them up 😩 She can get her knickers up by pulling on the sides but she can’t get them over her bum 😂 she is a skinny minnie but her bum.. it’s peachy!! 😂🍑 How can I help her to pull them up fully or do I just have to help and wait til she is a bit older? She is just 20 months so little arms too! 🥰